Several German shipping lines suspended calls at eastern Japanese ports, including Tokyo, because of fears crews could be exposed to radiation from the damaged Fukushima nuclear power plant.
Hapag-Lloyd, Germany's biggest ocean container carrier, has stopped calls at Tokyo and Yokohama and is re-routing cargo to Kobe.
Claus-Peter Offen, a leading shipowner with scores of container vessels on charter to leading ocean carriers, is also avoiding Japan's two largest container ports.
Ocean carrier Hamburg-Sud halted calls at Tokyo and Yokohama last week but is now deciding calls on a case by case basis related to weather conditions.
Tokyo and Yokohama handled 7.5 million 20-foot equivalent units in 2010, 38 percent of total Japanese box traffic, according to Alphaliner, the Paris-based analyst.
Most other leading ocean container carriers, including Maersk Line, are operating normal schedules to Japanese ports.
Air Cargo Unaffected
Germany's Lufthansa Cargo said disruptions to production in Japanese factories following the earthquake and tsunami earlier in the month have not affected the flow of air cargo exports.
"On the cargo side, we have not seen any dramatic decline in freight being loaded," Karl Ulrich Garnadt, the carrier's chief executive said.
Lufthansa in November almost doubled the number of weekly MD-11 freighter flights from Frankfurt to Tokyo and Osaka to 12 to take advantage of Japan Air Lines' exit from freighter operations.
-- Contact Bruce Barnard at email@example.com.